Circular knitting machine



March 21, 1939. A w KENT E1- A| 2,151,662

CIRC LAR KNITTING MACHINE Filed April 8, 1937 6 SheetsSh eet 1 Fig.1.

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March 21 1939.

A w. KENT ET AL CIRCULAR KNITTING' MACHINE Filed April 8, 1937 6 Sheets-Sheet 2 Fig. 2.

March 21, 1939. A. w. KENT ET AL CI RCULAR KNITTING MACHINE Filed April 8, '19s? 6 Sh ets-Sheet 3 nWszvmes:

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March 21, 1939. A. w. KENT ET AL CIRCULAR KNITTINGMACHINE Filed April 8, 1937 6 Sheets-Sheet 6 Fig. 13

Patented Mar. 21, 1939 UNITED STATES CIRCULAR KNITTING MACHINE Alfred Woodward Kent, Groby, and Henry Harold Holmes, Leicester, England, assignors to Wildt and Company Limited British company Leicester, England, a

' Application April 8,1931, Serial No. 135,780

In Great Britain April 16, 1936 7 Claims.

This invention relates to circular knitting machines and has particular reference to circular knitting machines or the double axially opposed needle cylinder type having independent latch needles.

The object of the invention is to provide, in a circular knitting machine ofthis type, means of a simple character for casting stitches off needles and subsequently opening the latches of the same needles, the purpose of this being, of course, to enable such needles to resume knitting at once when required.

The invention is intended for'application more especially to machines of the type aforesaid which include superimposed needle cylinders and double-ended latch needles as disclosed in British specifications Nos. 15,008 of 1900 and 24,290 of 1912.

The invention is applicable to both single and multi-feed knitting machines, and to machines of the stationary needle cylinder type as well as to those of the revolving needle cylinder type.

Accordingly the invention consists of the provision of means (hereinafter referred to as the casting oil means) adapted to cause needles to cast off after knitting at the feed, or at one or more than one feed as the case may be, and to return such needles to a normal position preparatory to knitting again, and in combination with the casting-off means latch opening means arranged so as to co-operate with the said needles when they are being restored to the normal position to effect the opening of the latches.

By the expression normal position is meant any position to which the needles may be moved after knitting at the feed or any feed to enable them to knit again in the ordinary way.

In the accompanying drawings,

Figure 1 is a view drawn diagrammatically and showing parts of two adjoining articles of a string of articles knitted in accordance with the invention.

Figure 2 is a view representing a development of so much of the two cam systems at one feed of a machine of the superposed rotary needle cylinder type as is necessary to illustrate one embodiment of the invention.

Figure 3 is a detail sectional view taken on the line III-IIIof Figure 2 and showing more clearly one of the cams of the casting-oft cam arrangement shown in that figure.

Figure 4 is an elevational view of some of the parts shown in Figure 3 as viewed fromthe outside of the machine.

. to be described.

Figures 6, 7 and 8 are detail plan views illustrating the operation of the cam shown in Figures 3 and 4.

Figure 9 is a side elevational view partly in section showing more clearly the latch opening means which are employed in conjunction with the casting-oil cam arrangement.

Figure'9a is a detail view hereinafter to be 10 described.

Figure 10 is another view of the same as viewed from the outside of the machine.

Figure 11 is a view similar to Figure 2 (but showing only part of a bottom cam system) illustrating another embodiment of the invention.

Figure 12 is a detail sectional view taken on the line XII-XII of Figure 11.

Figures 13 and 13a are elevational views illustrating the means which are employed to operate certain of the cams of the casting-01f cam arrangement shown in Figure 11 as will be hereinafter described, and

Figures 14, 15 and 16 are detail views illustrating the manner in which the said means operate.

Like parts are designated by similar reference characters throughout the drawings.

In Figure 1, I represents the lower end and 2 the top of two adjoining articles, i. e. hose, halfhose, three-quarter hose or socks, produced in string formation. At 3 are shown a few courses of plain knitting which, as will be seen, are interposed between the toe pouch 4 and a few courses of rib knitting 5 in the same article. An antirun welt 6 is provided at the lower extremity of this article and between this welt and a welt I which precedes the rib top 8 of the next article there are a few parting or separating courses 9 of plain knitted loops. The courses 9, the purpose ofwhich is to facilitate separation of the articles after knitting, can be effectively produced by employing in a machine of the superimposed rotary needle cylinder type either of the combined casting-off cam arrangements and latch opening means now to be described.

According to the particular embodiment illustrated in Figures 2-10, there is provided in the bottom cam box it of the machine just beyond the knitting location a:-in the direction of rotation of the needles, 1. e. the direction indicated by the arrow A in Figure 2-a casting ofl' cam arrangement comprising a fixed cam l l for action upon slider knitting butts such as l2 (Figures 3,

6 and 7) so as to lower the corresponding sliders position as they next approach the knitting location, or the next knitting location, as the case may be. A fixed guard cam II is provided in association with the two casting-oi! cams. The auxiliary cam I2 is arranged for movement to and from the operative position indicated in Figure 6 and according to its position it determines whether or not the slider knitting butts i2 shall engage the casting-oi! cam II and consequently whether or not the corresponding needles shall be caused to cast-off. The cam i2 is arranged so that when operative it engages the slider knitting butts i2 at the clearing height D, the sliders being raised to this height after leaving the stitch cam ll by means of a clearing cam II in order toclear the corresponding needles and enable them to cast oil.

' It'is convenient to mention here that a welt track II is provided in the bottom cam system of the machine, this track having at the entrance thereto a radially movable cam II for opening and closing the track at the appropriate times. Normally the cam I! is in to close the track ll. At those times when it is desired to form a welt, however, the said cam is withdrawn to open the track and those sliders having butts which are to enter the track must, of course, be prevented from being raised to clearing height after leaving the stitch cam II to enable the corresponding needle to retain their loops. For this latter purpose the clearing cam i1 is made vertically movable so that it can be moved, 1. e. lowered, at the appropriate times from the normal clearing position indicated in full lines in Figure 2 to the position indicated in dot-and-dash lines in that figure. When the cam it is in to close the track II it serves as a raise cam to assist in restoring to the clearing position those sliders and corresponding needles which are lowered by the fixed casting-on cam II.

The auxiliary cam i2 is of the radially movable bolt type and the bolt thereof is adapted to slide in the bifurcated upper part of a bracket which is conveniently formed with ears or lugs 2| by means of which it can be secured by screws to the bottom cam box ll. The bolt of the cam II is retained in position by means of a plate 22 attached by means of screws 23 to the top of the bracket 24 and the underside of said bolt is recessed at 24 to accommodate the head 25 of a vertically disposed spindle 26. This spindle is mounted so as to be capable of a turning movement in a boss 21 formed on the bracket 20 and at its lower end has rigidly secured thereto a lever 24 by means of which the spindle can be turned. The lever is adapted to be controlled from the existing timing gear of the machine or some other control gear by intermediate connections (not shown). The head 25 is shaped in the manner shown more clearly in Figure 5 and has a fiat face 29, which, when the cam i3 is in, i. e. operative, abuts against the rear face of the recess-24 (see Figures 3 and 6). The cam II has associated therewith a tension spring III which tends to move it into the operative position. 4 One end, of this spring is connected, to the bolt of the cam and the other end to the plate 22 aforesaid. Thus by turning the spindle 2' so that the head 2' is turned from the position indicated in Figure 6 into the position indicated in Figure 8, the cam II can be withdrawn against the action pf the spring 20 from an operative into an inoperative position. How normally I the spindle 24 is held so that the head 24 is in the position shown in'l 'igure 8. That is to say the cam I2 is normally held withdrawn, and is consequently inactive. At the appropriate time (determined by the control gear) vthe lever 28 is turned to bring the head into the position indicated in Figure 7, with the result that the cam i2 is allowed to spring half-way in. When in this position the said cam is close to the short butts ii of the heel and toe series of sliders but does not act on these butts so that the sliders pass the cam at clearing height. The cam is permitted to move half-way in. when it is being approached by the instep series of sliders, and is held in this.

spindle 26 is simultaneously turned to bring the head 25 into the position indicated in Figure 6 and the said cam is consequently permitted to spring into its fully operative position in which it causes the butts I2 of the instep sliders to follow the path indicated by small arrows in Figure 2 with the result that the corresponding needles cast-01f. Thus casting-off commences on the first instep needle and can be initiated on this same needle every time. Casting-oi! is terminated by the reverse action of the auxiliary cam l2.

The latch opening means for use in conjunction with the particular form of casting oil. means just described may be of any of the forms hereinbefore specified.

As shown more clearly in Figure 9, a latch opening cam member 22 shaped to provide a knife edge 24 to be presented to the needles such as between the spoons of the closed latches 36 and the needle hooks 31, is located at a suitable point above the fixed raising cam l4. When the needles are raised by the said cam after casting oi! the knife edge 34 enters the slight angular recess I00 (Figure 90) formed by the end of the closed latch and the receding curve of the needle book which by reason of the continued rise of the needles pass respectively in front of and behind the said edge, so that the latches are opened. The slope on the cam I4 is gradual so as not to raise the needles too abruptly into engagement with the knife edge 24.. The cam member consists of a small block recessed as at 28 and thinned down within the recess to provide the knife edge, and is mounted on the top cam box 39 of the machine at the appropriate height and in the appropriate position circumferentially in relation to the knitting position. This block is secured, for example by means of screws, to the lower end of a lever 40 which is pivotally mounted between its opposite ends on a pivot pin 4i suitably carried by a small bracket 42 attached to the top cam box. The cam member 33 is capable of yielding for the purpose herein alluded to by reason of the interposition of a compression spring 42 between the upper end of the lever 40 and the adjacent part of the bracket 42. To provide for accurate setting of the knife edge" in relation to the needle latches there is conveniently provided an adjusting screw 44 which is screwed into the lever 44 and adapted at its free end to abut against a downwardly extending projection or similar part, such as 45, formed or provided on the bracket 42. A look nut 48 is provided to set the screw 45 in any position to which it is adjusted.

The embodiment of the invention illustrated in Figures 11-16 will now be described. According to this embodiment, which in many respects is similar to the embodiment just described, there is provided in the bottom cam box 41 of the machine just beyond the knitting location a: a casting off cam arrangement comprising a fixed cast-off cam 48 for action upon the slider knitting butts indicated at 49 (Figures 11 and 12) so as to lower the sliders and corresponding needles to a casting oil level C, an auxiliary lowering cam 58 for directing the said butts into engagement with the fixed cam, and at a suitable distance clrcumferentially from the fixed castofl' cam 48 a fixed slider raising cam 5| for restoring the sliders and corresponding needles to clearing position, as they next approach the knitting location or the next knitting location. as the case may be. Between the cams 48 and 5|, guard cams such as 52' and 53 are conveniently provided to form a more or less horizontal path or track 54 for slider knitting butts to maintain the appropriate sliders in the casting oil position. Other guard cams such as 55 and 56 may be provided in association with the slider lowering and raising cams. As in the previously described embodiment, the auxiliary cam 58 in the present embodiment is arranged for movement to and from an operative position, and according to its position it determines whether the slider knitting butts 49 shall engage the casting off cam 48 or not and consequently whether the corresponding needles shall be caused to cast oil or not. The operative position of the said cam is indicated in dot-and-dash lines in Figure 12 and when operative it engages the slider knitting butts 49 at the clearing height D, the sliders being raised to this height by an inclined part 51 of the cam 55 after leaving the stitch cam 58 in order to clear the corresponding needles and enable them to cast off. The auxiliary cam 58 may be either pivotally or slidably arranged for movement into and out of this position and for this purpose is controlled from the existing timing gear of the machine by intermediate levers and linkage of any suitable character. In the specific example illustrated the said cam is of the radially movable bolt type and is engaged with a spring controlled lever 59 adapted in turn to be acted upon by a bolt 68 connected by means of a link 6| with a main operating lever 62 arranged in engagement with a gapped cam ring 63 on a control drum or disc 64 on the main control shaft 65 of the machine. The bolt portion 58' of the cam 58 is slidably mounted in a suitably drilled out part of a carrier block 66 which may be mounted either on the bed of the machine, or, as shown, on the' flange 61 of the bottom cam box. The block 66 is slotted as at 68 for reception of the lever 59 and the latter is pivoted between its ends on a pivot pin 69 which extends transversely through the block. Near its upper end the lever 59 is enlarged and. works in a recess 18 formed in the bolt 58', whilst at its lower end the said lever is yieldingly held against the inner faced the bolt 68 by means of a tension spring ll connected at one end to the lever and at the other end to the block 66. The bolt 68 is recessed as at 12 on itsinner face. The arrangement so far described is therefore such that so long as the lower end of the lever 59 is held forward by the bolt 68 as indicated in Figures 12 and 14 the upper end 01' the lever maintains the cam 58 withdrawn, 1. e. out, against the action of the spring ii. If now the bolt 68 is caused to move to the left (as viewed in Figures 13 and 14) the lower end of the lever 59 is allowed to drop into the recess 12 with the result that the cam 58 springs into the operative position indicated in dot-and-dash lines in Figure 12, i. e. it moves in. The timing of the cam into operation is such that it engages the first long knitting butt 49 of the instep series of sliders, as will be hereinafter more fully explained.

At one end the link 61 aforesaid is adjustably connected to the bolt 68 by means of a bifurcated coupling member 13 and at the other end is conveniently attached to the upper end of the main operating lever 62. This lever is pivoted at 14 on any suitable part of the machine frame and at its lower end is held in contact with the cam ring 63 by means of a tension spring 15. The gap in the ring is indicated at 16 and is of the form shown so that the lower end of the lever 62 at the appropriate times can drop to the bottom of the gap and subsequently be raised to its normal position in two steps. The control drum or disc 64 is racked round in a clockwise direction. Thus while the gap 16 moves step by step past the lower end of the lever 62 the latter first moves from its normal position E to position F and then from position F to position G prior to being moved again to the normal position. These movements are transmitted to the bolt 68 which first moves to the left from its normal position (Figure 14) to the position indicated in Figure and then moves to the right into the position indicated in Figure 16 prior to being restored to its normal position.

It is advantageous to provide in association with the auxiliary lowering cam 58 a movable auxiliary slider raising cam 11 for nullifying the casting oil action without necessarily withdrawing the auxiliary lowering cam 58 at any particular time. This cam 11 which is of the same form as the cam 58 is located immediately adjacent to the latter and when operative acts upon the slider knitting butts immediately after the lowering cam. The auxiliary raising cam 11 is adapted to be operated by a spring controlled lever 18 which is conveniently controlled by the same means as the lever 59 so that the cam 11 can be put into action without necessarily affecting the auxiliary lowering cam 58 which can be withdrawn subsequently. The cam 11 is timed to go into action so as to enable it to engage the first of the aforesaid series of long knitting butts with the result that the casting ofi can be commenced and terminated on the same needles notwithstanding the fact that it may occur for more than one course. The lever 18 is accommodated in a slot 19 in the carrier block 66 and is controlled by a tension spring 88 (see Figure 13).

The operation of the mechanism just described is as follows. For normal knitting the bolt 68 is held in the position indicated in Figure 14, in which position the lower end of the lever 59 is held forward whilst the corresponding end of the lever 18 is seated in the bottom of the recess 19. Consequently during normal knitting the cam 58 is out and the cam 11 is in. The bolt 68 is held in this position for as long as the lever 62 remains in the position E. At the commencement of casting-oil the lever 62 is caused to move to the position 1" result that the lower end of the lever ll drops into the recess 12 and the corresponding end of the lever II is held forward. Thus the cam ll moves in and the cam II is withdrawn and the timing of the cam ll into operation is such that it engages the first long knitting butt of the instep series of sliders. Thus casting. of! can be initiated on the same needle. While the short butt sliders are being lowered by the cm ",the lever 82 is moved into the position 0 and consequently the cam ll still remains inbut the recess 12 is brought opposite to the lower end of the lever 18. In these circumstances the cam' I1 will be prevented by the short butts from moving in until the last short butt has passed it. Simultaneously with the passing of the said last butt, however, the cam 11 moves in and thus nullitles or terminates the casting off action without there being any tion with this form of casting-off means are.

conveniently the same as those employed in the previously described embodiment of the invention.

For producing articles such as those shown in Figure l in string formation on a circular knitting machine of the superimposed needle cylinder type the latter is operated to produce plain knitting for one or more courses after knitting one article, e. g. after knitting a toe such as 4 of a hose, half-hose or like article, after which a transfer is made to rib knitting and then knitting is suspended on one set of needles for two or more courses to form an anti-run welt. Rib knitting is then resumed and the casting off mechanism is put into operation to cause the plain needles to cast oif their stitches to form a parting or separating courses of rib loops, the latch opening means function as aforesaid to open the needle latches of the bare needles before these reach the knitting position again. The casting oi! action may continue for a complete course or more-according to the arrangement and timing adopted, following which the casting off mechanism is rendered inefiective and two or three needles later (approximately) the welt cam is withdrawn for the purpose of making the welt of the next article, and when a welt of the re- .quired number of courses has been made rib knitting may be resumed; for example if a rib top or the like is required.

Other latch opening means which may be adopted are (a) a point arranged, for example obliquely disposed, to come between the latch and hook of any needle restored to normal position after casting off so as to open the latch by reason of the movement of the needle in relation to the point; (D). a brush arranged to act upon the latches of any needles previously'caused to cast off when such needles resume the normal position; (0) a revolving brush driven from the needles, or independently by small gears or in any other convenient manner, and arranged to work upon the latches of any needles moving back from the casting off position as aforesaid, or (d) a revolving member fitted with a circular series of latch opening elements which may be arranged on the inside of the needle circle and be individually movable by cam means for causing said elements to co-operate with individual needles, when needles previously caused to cast oi! move back to the normal position preparatory to knitting again. The said revolving member may be driven from the needles or independently like the brush.

Asrega'rds latch opening this may be facilitated by vibrating the needles vertically or sideways. For example and as shown in Figure 11, a step ll may be formed in the casting of! path or track I so as to impart a slight abrupt upxard movement to the needles with that end in If'desired, means may be provided for controlling the needles which have cast off as such needles approach the latch opening means so that they are in a favourable position to be acted upon effectively by the latch opening means. According to one arrangement advantageously employed in conjunction with a knife edge cam member, a cam or cam surface is provided in advance of the latch opening means for action upon the hooks or' heads of the empty needles for: the purpose of pressing and holding them back in their tricks. For example the cam surface may be provided on the back of the aforemove outwards in their tricks under centrifugal force.

other, said sliders having thereon knitting butts,

a cam'box associated with each cylinder and having therein cams for action on slider knitting butts, a casting-off cam arrangement which is 'providedin the bottom cam box beyond a knitting location, saidcam arrangement including a fixed cam for action upon slider knitting butts so as to lower the sliders and. corresponding needles to a casting-off level and a fixed slider raising cam for restoring sliders and corresponding needles to the normal position as they next approach the knitting location, and latch opening means for co-operating with the said needles when they are being restored to the normal position to effect the opening of the corresponding latches.

2. In a circular multi-feed knitting machine, superposed rotary needle cylinders, double-ended latch needles in said cylinders, needle operating sliders for transferring needles from one cylinder to the other, said sliders having thereon knitting butts, a cam box associated with each cylinder and having therein cams for action on slider knitting butts, a casting-off cam arrangement which is provided in the bottom cam box beyond each of more than one knitting location, said cam arrangement including a fixed cam for action upon slider knitting butts so as to lower the sliders and corresponding needles to a casting-off level and a fixed slider raising cam for restoring sliders and corresponding'needles to the normal position as they next approach the appropriate knitting location, and latch opening means for co-operating with the said needles when they are being restored to the normal position to effect the opening of the corresponding latches.

3. In a circular knitting machine, superposed rotary needle cylinders, double-ended latch needles in said cylinders, needle operating sliders for transferring needles from one cylinder to the 5 other, said sliders having thereon knitting butts,

a cam box associated with each cylinder and having therein cams for action on slider knitting butts, a casting-off cam arrangement which is provided in the bottom cam box beyond a knit- 10 ting location, said cam arrangement comprising a fixed cam for action upon slider knitting butts so as to lower the sliders and corresponding needles to a casting-oi! level, an auxiliary lowering cam for directing said butts into engagement 1 with the fixed cam, said auxiliary cam being arranged for movement to and from an operative position, and a fixed slider raising cam for restoring sliders and corresponding needles to the normal position as they next approach the knitting Q location, and latch opening means for co-operating with the said needles when they are being restored to the normal position to eifect the opening of the corresponding latches.

4. A combination according to claim 3, wherein there is provided in association with the auxiliary lowering cam a movable auxiliary slider raising cam, for the purpose herein described.

5. In a circular knitting machine, superposed rotary needle cylinders, double-ended latch Q needles in said cylinders, needle operating sliders for transferring needles from one cylinder to the other, said sliders having thereon knitting butts,

a cam box associated with each cylinder and having therein cams for action on slider knitting butts, acasting-oif cam arrangement which is provided in the bottom cam box beyond a knitting posed needle cylinders.

6. In a circular knitting machine, in combination, axially opposed needle cylinders, independent latch needles having needle hooks and closed latches in said cylinders, a cam box associated with each cylinder and having therein cams for 5 effecting the movements of the needles, a castingoil. cam arrangement which'is provided in one of said cam boxes beyond a knitting location, said cam arrangement including a cam for effecting a lowering movement of needles to a casting- 0 of! level and a cam for restoring needles to the normal position as they next approach the knitting location, and a cam member which is arranged above the needle path and has a vertical rear face and a rearwardly sloping face inter- 15 secting said rear face so as to provide a downwardly facing knife edge to be presented to the upper ends of said needles between the spoons of said closed latches and said needle hooks when the needles are being raisedto the aforesaid nor- 20 mal position to open said latches.

7. In a circular knitting machine, axially op double-ended latch needles in said cylinders, needle operating sliders for transferring needles from one cylinder to the other, said sliders having thereon knitting butts,

a cam box associated with each cylinder and having therein cams for action on said slider knitting butts, a casting-oi! cam arrangement which is provided in one of the cam boxes beyond a knitting location, said cam arrangement including .a cam for action upon said slider knitting butts and operative to lower the sliders and corresponding needles to a casting-oi! level and a slider raising cam operative to raise said sliders and corresponding needles to the normal position as they, next approach the knitting location, and latch opening means positioned above the needle path, and said sliderraising cam bringing said latches into contact with said latch opening means when said so needles arebeingraisedtoberestoredtothenormal position to elect the opening'of thec'orrespondinglatchss.

ALI'RID WOODWARD KENT. MY HAROID HOLMES. 

